Battery module with two cell blocks and battery

Abstract

The invention relates to a battery module (1) with two cell blocks (2, 3) comprising prismatic battery cells (5), wherein a cooling element (4) through which a cooling medium flows is arranged between the two cell blocks (2, 3), the cooling element (4) having venting channels (10) for the discharge of gases in the event of the overpressure relief elements (6) of the battery cells (5) opening. The battery module according to the invention is characterized in that the battery cells (5) in each cell block (2, 3) are arranged such that their overpressure relief elements (6) point towards the cooling element (4), and that their electrical cell contacts (7) are arranged on the opposite side facing away from the cooling element (4).

Description

[0001] The invention relates to a battery module with two cell bars made of prismatic battery cells of the type defined in more detail in the preamble of claim 1. The invention also relates to a battery with such battery modules.

[0002] Battery modules, particularly for so-called high-voltage batteries as defined in ECE 100R, which are used as traction batteries in vehicles, are known from the prior art. The individual battery cells used here typically require cooling, so cooling elements within such batteries are considered part of the prior art. Furthermore, it is common for the housings of the individual battery cells to contain pressure relief elements, which, in the event of overpressure occurring inside the battery due to a malfunction, rupture and allow gases and hot particles to escape into the environment.

[0003] German patent DE 20 2020 005 990 U1 describes a battery module with two rows of vertically arranged individual battery cells, between which a cooling element is positioned. This cooling element incorporates a venting channel at the top and bottom for releasing gases in the event of a pressure relief element being activated. This channel is then completed within the overall assembly by another element, such as a housing cover. The two rows of individual battery cells are arranged in such a way that the gases must first be guided into the channel within the cooling element via additional guide elements, which is complex and time-consuming.

[0004] From DE 10 2022 114 012 A1, a battery module for storing electrical drive energy for a vehicle is known, comprising a battery cell stack with several prismatic storage cells, each having a degassing device on a first side for degassing the respective storage cell. Furthermore, the battery module includes a cooling plate through which a cooling fluid flows for cooling the several storage cells, which is arranged on the first sides of the storage cells and has a recess in a region above the degassing devices.

[0005] Furthermore, DE 10 2017 212 223 A1 discloses a battery for an electrically powered motor vehicle, comprising a number of energy storage cells, each having an electrical connection and a cell housing with a housing opening closed with a burst membrane, and a cooling plate arranged between the cell housing and a cell degassing chamber with a feedthrough that is in contact with the housing opening, wherein the cooling plate has an inlet opening into the feedthrough for supplying a coolant to the cell housing, which is closed off by means of a closure that opens in the event of triggering.

[0006] From US patent 2023 / 0006298 A1, a supporting structure for battery cells in a vehicle battery system is known, wherein this supporting structure comprises a base plate and two side plates for receiving the battery cells, and wherein each side plate has a flange on its outer surface and each flange includes a fixing for attaching the supporting structure to an adjacent structure. The base plate includes a vent channel for discharging gases from battery cells in the event of thermal runaway of the battery cells.

[0007] German patent application DE 10 2017 117 354 A1 also describes a venting channel between two rows of vertically arranged battery cells. In such a configuration, cooling elements and venting channels may be alternately placed between multiple rows of battery cells. This allows heat from the hot venting gases to easily escape from the venting channels into the adjacent battery cells. This can pose a safety risk.

[0008] The object of the present invention is to provide a simple and efficient design for a battery module which requires few components, can be implemented in a lightweight and compact manner, and is also safe and easy to assemble.

[0009] According to the invention, this problem is solved by a battery module having the features of claim 1, and in particular those of the characterizing part of claim 1. Advantageous embodiments and further developments are described in the dependent claims. Furthermore, a battery with such battery modules also solves the problem.

[0010] In the battery module according to the invention, a cooling element through which a cooling medium flows is arranged between two cell blocks, and which also has venting channels for the removal of gases in the event of the overpressure relief elements of the individual battery cells opening. This largely corresponds to the prior art mentioned above.

[0011] According to the invention, it is now provided that the individual battery cells in each of the cell blocks are arranged such that their overpressure relief elements point towards the cooling element and that their electrical cell contacts are arranged on the opposite side, away from the cooling elements.

[0012] The battery module according to the invention enables a simple design in which the individual battery cells are brought into contact with the cooling element, for example by clamping, gluing, pressing, or similar means. This ensures effective cooling due to the cooling medium cooling the cooling element. Simultaneously, in the event of a thermal event where overpressure occurs in at least one of the individual battery cells and the overpressure relief element opens, the venting gas is dissipated via the cooling element. This has the advantage that the heat from the hot venting gases is distributed across the cooling element during dissipation and partially carried away by the cooling medium. This prevents the formation of particularly hot local areas, thereby significantly reducing the risk of thermal interference with neighboring cells. This also reduces the risk of thermal runaway of the entire battery.

[0013] The design, in which the electrical cell contacts, also known as cell terminals, are arranged on the opposite side according to the invention, also ensures that the venting gases do not reach the cell terminals due to their guidance in the channel within the cooling element. This is another crucial safety advantage because venting gases, which directly heat the cell terminals, transfer heat directly into the individual battery cells. If the venting gas were to flow out through the cell terminals of adjacent battery cells, the risk of extreme heating of these individual battery cells would be significantly higher than with the proposed design, which is therefore very safe.

[0014] According to a particularly advantageous embodiment of the invention, the individual battery cells of each cell block within the battery module are arranged such that they touch each other at their end faces within the cell block. This configuration is also described by those skilled in the art as a cell block with horizontally mounted individual battery cells.

[0015] According to a further highly advantageous embodiment, each cell block can consist of at least two superimposed rows of individual battery cells, which are preferably arranged horizontally in the manner described above. In a particularly favorable embodiment of the battery module according to the invention, the venting channels are formed as grooves on both sides of the cooling element and extend to the end faces of the cooling element. The venting channels are thus designed to run along each side of the cooling element and to discharge the venting gases at the end faces of the cooling element in order to avoid, as far as possible, close contact between the continuous battery cell and adjacent battery cells.In particular, the grooves on one side and the other side can be designed without connection to each other, so that in the event of thermal runaway of a single battery cell in one cell block, the single battery cells in the other cell block remain well protected from thermal influence.

[0016] According to a very favorable further development, it can be provided that a separate venting channel is provided for each of the rows in the cooling element, so that thermal influence between the at least two rows within the cell bar is avoided as far as possible.

[0017] The cooling element also has cooling channels for the cooling medium, in particular a liquid cooling medium, wherein the cooling channels comprise at least a supply and a return. A cooling medium, in particular a liquid cooling medium such as a mixture of water and antifreeze, can be guided through the cooling channels. In particular, the cooling element is supplied with the cooling medium in the area of ​​a connection which is connected to a supply channel, and the cooling medium is drawn off again from a connection which is connected to a return channel. Preferably, this can be done from one side, i.e., one of the end faces of the cooling element, so that at the other end face only a deflection of the cooling medium from the supply to the return is necessary. This deflection does not have to be arranged outside the cooling element, but can preferably also be integrated into it.

[0018] Another very advantageous embodiment of this design can provide that the cooling channels for each row within the cell block comprise exactly one supply channel and exactly one return channel. This guarantees good cooling while simultaneously ensuring a simple design of the cooling element.

[0019] According to a particularly advantageous embodiment of the battery module according to the invention, the cooling element itself can be made of a non-combustible, highly thermally conductive material. In a further advantageous embodiment, the cooling element can therefore be manufactured as an extruded profile made of aluminum or an aluminum alloy. This combines the simple and efficient manufacturability of the required cross-sectional shape with good thermal conductivity and the fact that the material is non-combustible and can therefore efficiently dissipate the venting gases through the venting channels into the environment.

[0020] Another highly advantageous embodiment provides that the upper and lower edges of the cooling element project beyond the cell bars of the individual battery cells and are connected to a battery housing. The cooling element, which may be made from an extruded aluminum profile, can thus perform an additional function. Its height extends above the two cell bars of the preferably horizontally arranged individual battery cells in preferably two rows. A battery housing can then be bonded, screwed, or otherwise connected to these edges of the cooling element, so that the cooling element simultaneously serves to stiffen the battery housing.By using the cooling elements as additional stiffening elements, the otherwise typical separate stiffening elements of the battery housing can be completely or partially eliminated, making the battery housing simpler, lighter, and more efficient to manufacture and assemble. This simplifies the design in terms of the number of components required, resulting in a more compact and lighter overall structure. Consequently, a higher energy density of the battery module can be achieved.

[0021] Several such battery modules can be used in the battery housing. When these are arranged adjacent to each other, their cooling elements support the housing base and the housing cover. Between the cell bars of the adjacent battery modules, whose electrical cell terminals are aligned, the electrical connections, the necessary electronics, and the like can then be reliably arranged.

[0022] This makes it possible to implement a battery according to the invention with at least two such battery modules.

[0023] Further advantageous embodiments of the battery module or the battery according to the invention can also be seen from the exemplary embodiment, which is described in more detail below with reference to the figures.

[0024] This shows: Fig. 1 a three-dimensional view of a battery module according to the invention; Fig. 2 a schematic cross-sectional view through the area marked II-II in Fig. 1; and Fig. 3 a section of a battery with two such battery modules.

[0025] In the presentation of the Fig. Figure 1 shows a battery module designated as a whole by 1. It consists of a first cell block 2 and a second cell block 3. Both cell blocks 2 and 3 are arranged adjacent to a cooling element 4. Each of the two cell blocks 2 and 3 consists of two rows of horizontally arranged individual battery cells 5. Only some of these individual battery cells 5 are marked with the reference numeral 5. In the Fig. Figure 1, at the front left, shows one of the individual battery cells 5, including its hidden lines. It can be seen that a pressure relief element, labeled 6, points towards the cooling element 4. On the opposite side, away from the cooling element 4, are the electrical connections of the individual battery cell, labeled 7, which are also referred to as cell terminals. Each of the cell blocks 2, 3 is configured such that the pressure relief elements 6 of all individual battery cells 5 point towards the cooling element 4, and the cell terminals 7 of all individual battery cells 5 point in the opposite direction. In the embodiment shown here, each of the cell blocks 2, 3 consists of the two rows of horizontal individual battery cells 5, which are arranged one above the other.

[0026] In the sectional view of the Fig. Figure 2 shows four of the individual battery cells 5 in sections. The cooling element 4, which consists, for example, of an extruded aluminum profile, includes a supply line (designated 8) and a return line (designated 9) for a liquid cooling medium for each cell row. This cools the individual battery cells 5 during normal operation and, if necessary, also warms them after a cold start or in preparation for a charging process using the then warmer cooling medium.

[0027] As mentioned above, each of the individual battery cells 5 has an overpressure relief element 6, which is also shown in the illustration of the Fig. 2 is shown again in each case. This overpressure relief element 6 corresponds to venting channels 10 within the cooling element 4. If a thermal event occurs in one of the individual battery cells 5, causing a critical overpressure to build up, the overpressure relief element 6 of this individual battery cell 5 opens so that the gases can escape via the venting channel 10 within the cooling element 4. They are released via the venting channel 10 on both sides of the battery module 1, as shown in the illustration of the Fig. 1. Also, at the front left and rear right, they are discharged from cooling element 4. They can then be selectively discharged from this area into the surrounding environment.

[0028] The hot venting gases are cooled slightly by the cooling element 4 and, more importantly, kept away from the cell terminals 7, through which they could introduce a large amount of heat into neighboring battery cells 5, since the cell terminals are electrically - and therefore also thermally - connected to the interior of the battery cell 5, thus creating the risk of an undesirably high heat input into the battery cell 5.

[0029] Within a representation of the Fig. In the partial section of battery 11 shown in Figure 3, the cooling elements 4 can now perform an additional function. The section of battery 11 shown here consists of two battery modules 1, each comprising the two cell bars 2, 3 and the cooling element 4. The cooling elements 4 are designed such that they extend slightly beyond the thickness of the cell bars 2, 3 in a vertical direction h. This allows a housing cover 12 and a housing base 13 of a battery housing to be screwed, glued, or otherwise connected to the cooling elements 4 in order to increase the rigidity of a battery 11 consisting of several such battery modules 1, in addition to their cooling and gas removal functions.

[0030] The in Fig.The partially shown structure in Figure 3 also offers the possibility of accommodating the electrical connections of the cell terminals 7 and the arrangement of electronic components, for example for battery management, charge equalization between the individual battery cells 5, and the like, in the area outlined by a dashed line and labeled 14. This area labeled 14 is very well protected in the event of thermal runaway from an individual battery cell 5, as the venting gases are discharged into the environment via the venting channels 10 in the cooling element 4. Heat input into the individual battery cells 5 via the electrical contacts is thus prevented. The electronics intended for battery management can therefore continue to be used, at least for a certain period, to implement safety concepts such as the shutdown of individual battery cells 5 or the like.

Claims

[1] Battery module (1) with two cell bars (2, 3) made of prismatic battery cells (5), wherein a cooling element (4) through which a cooling medium flows is arranged between the two cell bars (2, 3), wherein the cooling element (4) has venting channels (10) for the removal of gases in the event of overpressure relief elements (6) of the battery cells (5) opening, characterized by , that the individual battery cells (5) in each cell block (2, 3) are arranged such that their overpressure relief elements (6) point towards the cooling element (4), and that their electrical cell contacts (7) are arranged on the opposite side away from the cooling element (4). [2] Battery module (1) according to claim 1, characterized by , that the individual battery cells (5) of each cell block (2, 3) are arranged such that the end faces of adjacent individual battery cells (5) touch within the cell block (2, 3). [3] Battery module (1) according to claim 1 or 2, characterized by , that each of the cell bars (2, 3) is formed from at least two superimposed rows of battery individual cells (5). [4] Battery module (1) according to any one of claims 1 to 3, characterized by , that the venting channels (10) are formed in the form of grooves on both sides of the cooling element (4), the venting channels (10) extending to the end faces of the cooling element (4) in the direction in which the battery individual cells (5) are arranged in a row. [5] Battery module (1) according to claims 3 and 4, characterized by , that a separate venting channel (10) is provided for each of the rows of battery individual cells (5). [6] Battery module (1) according to any one of claims 1 to 5, characterized by , that the cooling element (4) has cooling channels for the cooling medium, in particular a liquid cooling medium, wherein the cooling channels comprise at least a supply channel (8) and a return channel (9). [7] Battery module (1) according to claim 3 and 6, characterized by that the cooling channels for each of the rows comprise exactly one supply channel (8) and one return channel (9). [8] Battery module (1) according to any one of claims 1 to 7, characterized by , that the cooling element (4) is made of a non-combustible, highly thermally conductive material. [9] Battery module (1) according to any one of claims 1 to 8, characterized by that the cooling element (4) is manufactured as an extruded profile made of aluminium or an aluminium alloy. [10] Battery module (1) according to any one of claims 1 to 9, characterized by , that the upper and lower side edges of the cooling element are designed to project transversely to the direction of the arrangement of the individual battery cells (5) over the cell bars (2, 3) and are connected to a battery housing. [11] Battery (11) with at least two battery modules (1) according to any one of claims 1 to 10.

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